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Title: What is the resistance (in ohms) of a 75-W lightbulb in a 120-volt circuit? Post by: tonichilds83 on Oct 6, 2012 What is the resistance (in ohms) of a 75-W lightbulb in a 120-volt circuit?
Title: What is the resistance (in ohms) of a 75-W lightbulb in a 120-volt circuit? Post by: zzz on Oct 6, 2012 Recall Ohm's Law: V = IR
and that power: PW = IV if we change Ohm's law around: I = V/R and plug this into power equation: PW = (V/R)V = V²/R PW = V²/R 75 = (120)²/R R = 192 ohms |